01. Day of Week

Решение със if else:

import java.util.Scanner;

public class DayOfWeek {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = Integer.parseInt(scanner.nextLine());

        if (num == 1) {
            System.out.println("Monday");
        } else if (num == 2) {
            System.out.println("Tuesday");
        } else if (num == 3) {
            System.out.println("Wednesday");
        } else if (num == 4) {
            System.out.println("Thursday");
        } else if (num == 5) {
            System.out.println("Friday");
        } else if (num == 6) {
            System.out.println("Saturday");
        } else if (num == 7) {
            System.out.println("Sunday");
        } else {
            System.out.println("Error");
        }
    }
}

Решение със switch:

import java.util.Scanner;

public class DayOfWeek {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = Integer.parseInt(scanner.nextLine());

        switch (num) {
            case 1:
                System.out.println("Monday");
                break;
            case 2:
                System.out.println("Tuesday");
                break;
            case 3:
                System.out.println("Wednesday");
                break;
            case 4:
                System.out.println("Thursday");
                break;
            case 5:
                System.out.println("Friday");
                break;
            case 6:
                System.out.println("Saturday");
                break;
            case 7:
                System.out.println("Sunday");
                break;
            default:
                System.out.println("Error");
                break;
        }
    }
}

Решение с тернарен оператор:

import java.util.Scanner;

public class DayOfWeek {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = Integer.parseInt(scanner.nextLine());

        System.out.println(
                num == 1 ? "Monday" :
                        num == 2 ? "Tuesday" :
                                num == 3 ? "Wednesday" :
                                        num == 4 ? "Thursday" :
                                                num == 5 ? "Friday" :
                                                        num == 6 ? "Saturday" :
                                                                num == 7 ? "Sunday" : "Error");
    }
}

Решение с масив и тернарен оператор:

import java.util.Scanner;

public class DayOfWeek {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = Integer.parseInt(scanner.nextLine());

        String[] dayOfWeek = new String[]{"Error", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"};

        System.out.println(dayOfWeek[(num > 0 && num < dayOfWeek.length ? num : 0)]);
    }
}